In order to promote the healing process of open wounds, in addition to the usual suctioning of wound secretions, it is known to continuously or intermittently subject the wound to a defined negative pressure. The migration of the epithelial tissue and the subcutaneous tissue surrounding the wound toward the wound is thereby increased and a faster wound closure is achieved.
The wound to be treated must thereby be sealingly closed by suturing or stapling so that a negative pressure can be built up on the wound by installing a suction tube. If it is not possible to seal off the wound from atmospheric pressure, for example, in the case of extensive wounds, the wound is sealed off by covering it with adhesive bandages or wound dressings.
In order to discharge the accumulation of secretions occurring during the natural healing process and during a supportive negative pressure treatment, a drainage tube is commonly placed into the wound and connected to a medical suction device with a secretion receptacle. Such a wound treatment device has previously been described, for example, in EP 0 853 950 B1 In which a special wound dressing pad. In order to discharge extract secretions from a wound into a secretion receptacle, a certain pressure differential between the pressure in the wound cavity and the atmospheric pressure, i.e., a certain ventilation of the wound cavity, must be provided. For example, germs in the surrounding air must not enter the wound. It is thus necessary to appropriately filter the ventilation air supplied to the wound.
The ventilation of the wound cavity is particularly problematic when the wounds to be treated are internal wounds or when the wound must be closed airtight via a wound dressing.
A portable wound treatment apparatus is described in EP 0 865 304 B1 for aspirating secretions out of a superficial wound covered with an air-tight surgical wound covering in which a suction pipe provided with additional lumen is connected to the surgical wound covering. The additional lumen allow air to be supplied to the suction point. The suction apparatus must be specially configured to control the air supply through the ventilation lumen.
In order to aspirate secretions out of body cavities, DE 43 06 478 A1 describes, in addition to the drainage tube leading to the suction apparatus, providing an additional tube through which preferably air is conducted to the suction point. The suction apparatus must also be equipped with corresponding measurement, control, and filtering instruments to control this air supply. Using a conventional medical suction apparatus equipped only with a suction inlet is not possible with this drainage device.
WO 2009/071933 A2 describes a negative pressure wound therapy which also uses a wound dressing to seal the wound. A sealed suction tube, which is connectable to a vacuum source and which is equipped with a perforated drain, is thereby introduced through the wound dressing into the wound cavity. In order to allow for a ventilation of the wound cavity near the suction point, an additional ventilation tube must be introduced through the wound dressing in a sealed manner. A bacterial filter is disposed at the end of the ventilation tube in a separate housing equipped with an air inlet opening. This bacterial filter is set to a fixed permeability which determines the intensity of the ventilation. In order to make ventilation possible when the given size of the pores of the bacterial filter is 0.2 μm, the bacterial filter must be designed as a relatively large-scale membrane filter. The scope of application of this solution is very limited due to the required separate filter housing and separate ventilation tube. Positioning and sealing two separate tubes results in an increased effort, specifically when caring for internal wounds that are not closed by a wound covering. Another disadvantage is that with a ventilation tube closed by a tube clamp, humidity can enter the bacterial filter through the air inlet opening of the filter housing so that the filter will become permanently inoperative due to its hydrophobic properties. This is particularly disadvantageous for mobile applications and applications where the drainage tube remains in the wound while using sanitary facilities.
DE 10 2011 052 735 A1 describes a multi-lumen medical drainage tube in which the suction lumen flows into an axial ventilation opening at its proximal end.
U.S. Pat. No. 4,735,606 describes a medical drainage apparatus in which the distal end of a multi-lumen drainage tube is placed into a body cavity, whereas the proximal end of the drainage tube is connected to a negative pressure source via collection receptacles. This drainage apparatus is connectable to a conventional negative pressure source having only one suction inlet. The problem with this solution is that a regulatable ventilation and filter unit must first be connected to the proximally open ventilation lumen so that it is sealed by a frictional connection. If this ventilation and filter unit is not or is not correctly connected, germs from the surrounding air may get into the wound to be treated. Although this medical drainage device is also connectable to conventional suction apparatuses equipped with only one suction inlet, it is not satisfactory with regard to handling, constructional design, and safety due to the type of ventilation used. The necessity of controlling the intensity of the ventilation by means of an adjustable valve in accordance with the situation across the described wide control range makes it necessary for the filter used to have a permeability, and thus a pore size, that does not meet current requirements imposed on bacterial filters.
DE 31 27 249 A1 describes a surgical drainage device with an adapter from a one-lumen to a three-lumen tube with an axial ventilation opening. Sterility cannot be provided due to the required assembly prior to use.
DE 43 06 478 A1 describes a drainage device in which a suction tube having a plurality of lumen on the patient side gives way to two separate tube sections at its proximal end, wherein a bacterial filter is embedded in the separate tube section of the additional tube.
The known technical solutions are not satisfactory with regard to compactness and handling. These solutions are in particular not adapted for use in soft tissue drainages in which the proximal end of a single suction tube is pulled with a needle through the tissue layers next to the opening of the wound from the inside to the outside.
In an embodiment, the present invention provides a medical drainage tube for treatment of wounds using a negative pressure generated by a medical suction apparatus which includes a suction tube, a suction connector, and a ventilation sleeve. The suction tube comprises at least one suction lumen, and at least one ventilation lumen comprising a ventilation lumen outer wall and a radial ventilation opening. The suction connector is arranged at a proximal end of the suction tube spaced apart from the radial ventilation opening. The ventilation sleeve is arranged at the radial ventilation opening so as to coaxially surround the suction tube. The ventilation sleeve comprises a ventilation sleeve wall comprising a ventilation sleeve inner wall arranged towards the suction tube, an annular groove arranged in the ventilation sleeve inner wall, a filter compartment arranged in the ventilation sleeve wall, a bacterial filter undetachably arranged in the filter compartment, and an air inlet opening arranged in the filter compartment. The annular groove is configured to communicate with the radial ventilation opening. The bacterial filter is configured to communicate with the annular groove. The air inlet opening is configured to connect the bacterial filter with the atmosphere. A part of the at least one ventilation lumen between the annular groove and the proximal end of the suction tube is sealed off.